This invention generally relates to adjusting devices for machine tools and is specifically concerned with a device for presetting the position of a plurality of machine tools relative to one another.
Devices for adjusting the position of machine tools are known in the prior art. However, before such adjusting devices are described, a brief description of the mechanical context of such devices will be given.
Some machining operations require a dual spindle application. The spindles are generally operated simultaneously by a program to perform the same movement to machine identical parts. For example, wing spars of aircraft are commonly machined from raw material, such as aluminum blocks. When milling cavities and creating webs in the aluminum blocks, it is critical that the cavities and webs be milled and created identically with respect to identical parts. The aluminum blocks are generally supported by a machine that permits horizontal operation of its spindles in an area about 100 feet long and 30 feet high. Acceptable tolerances in such an operating environment are within xc2x11.00 inch.
To reduce the risk of unacceptable tolerances occurring, dual spindle machine tools must be set up the same. To accomplish this, such tools are commonly supported by thermal gripping adapters. One end of each adapter has a bore therein for receiving a respective tool. Another end of each adapter is provided with a shank that is adapted to engage a respective spindle. The diameter of each bore is slightly smaller than that of the machine tools. A xe2x80x9cshrinkerxe2x80x9d includes a coil that may be electrically charged to heat the adapter. This causes the bore to expand. In this expanded condition, the bore may receive a respective tool. The tool is inserted into the bore until a collar or clamp engages the adapter. At this juncture, the adapter is permitted to cool. As it cools, the bore contracts to grip the tool, creating an interference fit between the tool and the adapter.
To reduce the risk of unacceptable tolerances occurring, the tools are precisely pre-set in the clamps and then precisely gripped by the adapter. Ideally, the tools must be pre-set within the clamps within xc2x10.0005 inch of each other and then gripped by the adapters within xc2x10.0005 inch of each other. This produces an acceptable tolerance of xc2x10.001 inch.
To minimize unacceptable tolerances with respect to positioning the tools relative to respective clamps, position adjustment devices were developed in the prior art. In one of the most common designs, a clamp is releasably supported relative to a supporting surface by a xe2x80x9cpotxe2x80x9d. A measuring unit is aligned with the clamp in a spaced relation relative to the clamp. A tool may be placed in the clamp and the measuring unit may engage the tool. A fine adjustment screw is adapted to be adjusted to vary the position of the tool relative to the clamp. Once a desired position is achieved, the clamp may be tightened to hold the tool in a fixed position. Once the clamp is tightened, the tool with the clamp tightened thereto may be removed from the pot and inserted into the thermal gripping adapter. Additional tools may be positioned in additional clamps with the same device by following the same sequence of steps.
While such prior art devices are capable of positioning tools in clamps, the applicants have observed a shortcoming associated with such devices. For example, positioning successive tools through the use of a single pot is inefficient and complicated in that it requires the successive steps of supporting and removing successive tools and clamps.
Clearly, there is a need for a device for making fine adjustments to the position of a plurality of machine tools which are easier and faster to use than prior art adjusting devices. Ideally, such a position-adjusting device would minimize the cost of setting up tools for operation in a dual spindle machine.
Generally speaking, the invention is directed to a device for adjusting the position of a machine tool. The device comprises a surface plate defining a flat surface. A plurality of clamps are supported relative to the flat surface. Each clamp is adapted to support a tool. An adjustment member is adapted to adjust each tool relative to a respective one of the clamps.
The method may provide a clamp and a measuring device spaced apart from the clamp. A tool may be inserted into the clamp. Next, the tool may be engaged with the measuring device. Now, the position of the tool may be adjusted to achieve a desired measurement by the measuring device. Finally, the clamp may be tightened upon the tool to hold the tool in a fixed position. At least one additional clamp may be provided and the clamps may be co-planar relative to one another. An additional tool may be inserted in the additional clamp. The measuring device may be aligned with the additional tool after the first clamp is tightened to hold the first tool in a fixed position. With the measuring device in a fixed position, the additional tool is engaged with the measuring device. The position of the additional tool is adjusted to achieve a measurement by the measuring device identical to that of the first tool. The additional clamp is tightened upon the additional tool to hold the additional tool in a fixed position.
Advantageously, the adjustment device is easily and highly controllable for fine position adjustments. A common placement of clamps reduces the risk of error occurring in positioning tools and assists in holding the tools in a fixed position that is common to one another. The method of the invention advantageously provides an easy technique for positioning tools and holding the tools in a fixed position relative to one another.